Horton Plaza Park could get a belated 100th birthday present of $8.5 million if plans approved Wednesday win the nod from the City Council next year.

The Centre City Development Corp. board unanimously endorsed a plan by Westfield America, owner of the Horton Plaza shopping center, to demolish the former Robinson’s department store building just south of the historic park, that is mostly vacant, and replace it with a hardscaped square.

The deal, expected to go before the council in January, would settle a $35.1 million debt Westfield theoretically faces, stemming from the development agreement with the original builder, Ernest W. Hahn, back in the 1980s.

Richard Steets, Westfield’s senior executive vice president for U.S. corporate development, urged CCDC to speed up the project to be ready by Dec. 31, 2013.

“We think this urban plaza will be perfectly suited for New Year’s Eve 2013,” he said.

The plan calls for Westfield to give the 37,000-square-foot Robinson’s site back to the city, take over plaza maintenance and schedule more than 200 events in the park for 25 years. In return, Westfield would be relieved of the $35.1 million in profit-sharing payments that are projected through 2035 but are not guaranteed.

The city would be responsible for the estimated $8.5 million construction of the new plaza and restoration of Horton Plaza Park, with the money coming from Westfield property-tax payments and other redevelopment funds. The park's fountain has been turned off for about two years because of maintenance issues.

Famed San Diego architect Irving J. Gill redesigned the park and added the fountain in 1910 to coincide with the opening of the U.S. Grant Hotel across the street.

Downtown founder Alonzo E. Horton had set aside the plaza after he built the earlier Horton House hotel on the Grant site in 1870; he sold the park to the city in 1894 for $10,000.

CCDC spokesman Derek Danziger said public workshops and design work would take place next year in advance of demolition and construction. The current 1910 layout of Horton Plaza park and its fountain would remain largely intact.

“I think we can create a really great, beautiful urban plaza and still honor that historic design,” Steets said.

Paul Mara, a consultant at Keiser Marston, said the department store valuation was based on its highest and best use as a retail location, $568 per square foot. But he acknowledged that if the site were cleared the land would be worth about $400 per square foot based on comparable market value.

In negotiations, he said, both sides reduced their expectations to arrive at a deal -- Westfield taking less for its property and the city taking less in profit sharing credits.